Bob54,
A relative of mine had a similiar situation. Her son was 10 or 11 and ready for camp. She took him to a Uroglogist who prescribed DDAVP which is Desomopressin. The boy went to the camp nurse every night for his “allergy medication”. Obviously, the camp nurse knew what it was for. He had a wonderful summer except for one accident. He called his mother crying hysterically, she advised him to turn over the mattress put on dry linen and she went the next day and took care of things. ( washed the mattress,linenes, sprayed it with lysol etc). None of the kids knew. Apparently, he was not allowed to drink within an hour or two of going to sleep. He may have had too much to drink before going to sleep, because, otherwise, she said it worked wonders.
Hatzlocha, I hope your son gets to go to camp and has a wonderful time.
P.S. Nocturnal Enuresis (nightime bedwetting) is caused by overactivity or instability of the detruser muscle of the bladder. So, this issue is not his fault and he should not be deprived of the camp experience because of this.